Many people take up running for the physical and mental health benefits.
Not exercising enough, for example, is one of the leading causes of disease and death globally.
However, in some cases it could prove dangerous, if taken too far.
An expert has explained more about a deadly condition that can affect those taking part in high-intensity exercise including running.
Dubbed a “silent killer” due to the fact symptoms can take days to appear, rhabdomyolysis is a condition that occurs when damaged muscle tissue releases proteins and electrolytes into the bloodstream.
These released substances can then damage organs such as the heart and kidneys.
In an article for Runners World, Professor William Roberts wrote: “Almost anyone who works out to improve performance will release or leak some creatine kinase into the bloodstream, but this becomes a problem when the muscle cell releases contents like potassium or myoglobin, which causes complications.”
He continued: “It is a bad idea for anyone to surprise muscles with an unexpected volume of work that is well beyond the usual level (which is one of the reasons for the 10 percent rule), since rhabdomyolysis can lead to renal failure and even death from arrhythmia.”
But he added: “The likelihood that you would develop rhabdomyolysis is slim unless you are drastically increasing your training volume or intensity, which can cause all kinds of overuse injuries.”
The Centres for Disease Control and Prevention (CDC) acknowledges that athletes are at increased risk for rhabdomyolysis, which is also known as rhabdo.
But it also warns that people in certain jobs could be at risk.
“Anyone can get rhabdo, but some workers are at a higher risk than others,” it says.
“People who work in hot environments and/or perform strenuous physical tasks have a higher chance of getting rhabdo.”
These jobs include firefighters, police officers, first responders, people who work in hot environments, such as farm and construction workers or forge workers and military service members.
The Cleveland Clinic also lists high-intensity exercise as one cause of rhabdo.
“Jumping into an exercise program too fast can lead to rhabdomyolysis when your muscles don’t have time to heal after an intense workout,” it states.
But the clinic also warns it could be triggered by:
- Injury or trauma such as a burn or crushing injury
- Severe dehydration and overheating
- Medications
- Substance use disorder
- Long periods of inactivity
- Certain medical conditions.
Symptoms
Some people will not display any symptoms of rhabdo. For others the most common signs include:
- Muscle cramps, aches, or pains that are more severe than expected
- Dark urine
- Feeling weak or tired, unable to complete job tasks or finish a workout routine.
“Symptoms can appear any time after muscle injury,” the CDC says.
“For some people, symptoms might not start to appear until several days after the initial injury.
“If you have any of these symptoms at any time, do not ignore them. Seek medical treatment right away.
“Earlier diagnosis means an earlier start to treatment and a greater chance of recovery without permanent health effects.”